Countershaft and Reverse Idler Gear Inspection

Countershaft and Reverse Idler Gear Inspection

Countershaft Disassembly and Reassembly

- Using micrometer, check diameter of countershaft (1) and needle bush (2) as shown. If measured value is out of specification, replace countershaft and/or bush.

Countershaft diameter (standard)










- Measure width "a" of low speed gear shift fork and groove width "b" of low speed gear synchronizer sleeve and then calculate clearance "c" as follows:






If clearance exceeds limit, replace gear shift fork and sleeve.

Clearance "c" between fork and sleeve
Standard: 0.2 - 0.5 mm (0.008 - 0.020 in.)
Limit: 1.0 mm (0.039 in.)





- Check clearance "a" between synchronizer ring (2) and gear (1), key slot width "b" in synchronizer ring and each chamfered tooth of gear and synchronizer ring and replace with new one, if necessary. Also, check gear tooth.

Clearance "a" between synchronizer ring and gear (Countershaft) (1st and 2nd)
Standard: 1.0 - 1.4 mm (0.040 - 0.055 in.)
Service limit: 0.5 mm (0.020 in.)

Key slot width "b" (1st and 2nd synchronizer ring)
Standard: 10.0 - 10.2 mm (0.394 - 0.401 in.)
Limit: 10.45 mm (0.411 in.)






- Using cylinder gauge (1), check inside diameter of countershaft 1st and 2nd gears (2). If measured value exceeds specification, replace it.

Countershaft 1st and 2nd gears diameter
Standard: 40.000 - 40.025 mm (1.5748 - 1.5757 in.)





- Check oil clearance between reverse idler gear (2) and shaft (1) measuring inside diameter "a" of gear and diameter "b" of shaft and calculate as follows:






If clearance exceeds limit, replace gear and shaft.

Oil clearance "c" between reverse idler gear and shaft
Standard: 0.016 - 0.045 mm (0.0006 - 0.0018 in.)
Limit: 0.13 mm (0.005 in.)





- Check clearance between reverse idler gear (2) and lever (1) of reverse gear shift link.
If clearance exceeds limit, replace gear and lever.

Clearance between reverse idler gear and lever
Standard: 0.05 mm - 0.25 mm (0.002 - 0.010 in.)
Limit: 0.5 mm (0.020 in.)